From: Dan Malek <dan@embeddededge.com>
To: Brian Kuschak <bkuschak@yahoo.com>
Cc: linuxppc-embedded@lists.linuxppc.org
Subject: Re: virt_to_phys() on 440
Date: Mon, 08 Sep 2003 18:03:48 -0400 [thread overview]
Message-ID: <3F5CFCC4.9050309@embeddededge.com> (raw)
In-Reply-To: 20030908213638.4000.qmail@web40910.mail.yahoo.com
Brian Kuschak wrote:
> I think the virt_to_phys() function is incorrect for
> PPC440. It should call iopa for all 4xx, not only the
> 405.
You won't get any argument for me, but everyone else
will argue with us. A long, long time ago I got spoiled
using, designing, and implementing orthogonal VM functions.
When I bring up this discussion I'm continually reminded
that Linux isn't this way, it's supposed to be lightweight
and fast.....meaning you have to use different functions
to manage different memory regions with subtle side effects.
> .... By chance, it happens to work currently if the
> address is in SDRAM, but is always incorrect for
> ioremapped addresses. virt_to_bus() does the right
> thing.
It will likely always be this way. You have to keep track
of your own mappings and compute what you need from that,
especially when mapping things for DMA.
-- Dan
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2003-09-08 22:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-08 21:36 virt_to_phys() on 440 Brian Kuschak
2003-09-08 22:03 ` Dan Malek [this message]
2003-09-08 22:08 ` Eugene Surovegin
2003-09-08 22:14 ` Matt Porter
2003-09-08 22:36 ` Brian Kuschak
2003-09-08 23:26 ` Matt Porter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3F5CFCC4.9050309@embeddededge.com \
--to=dan@embeddededge.com \
--cc=bkuschak@yahoo.com \
--cc=linuxppc-embedded@lists.linuxppc.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).